[1] Guangzhou Med Univ, Guangzhou Women & Childrens Med Ctr, Dept Child Hlth Care, Guangzhou, Peoples R China
[2] Guangzhou Med Univ, Guangzhou Women & Childrens Med Ctr, Neonatal Med Ctr, Neonatal Unit, Guangzhou, Peoples R China
[3] Childrens Hosp Philadelphia, Div Neonatol, Philadelphia, PA 19104 USA